[ previous ] [ Contents ] [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 10 ] [ 11 ] [ 12 ] [ 13 ] [ A ] [ B ] [ C ] [ D ] [ E ] [ F ] [ G ] [ next ]

Debian Policy Manual
Appendix C - Source packages (from old Packaging Manual)


The Debian binary packages in the distribution are generated from Debian sources, which are in a special format to assist the easy and automatic building of binaries.

There was a previous version of the Debian source format, which is now being phased out. Instructions for converting an old-style package are given in the Debian policy manual.


C.1 Tools for processing source packages

Various tools are provided for manipulating source packages; they pack and unpack sources and help build of binary packages and help manage the distribution of new versions.

They are introduced and typical uses described here; see dpkg-source(1) for full documentation about their arguments and operation.

For examples of how to construct a Debian source package, and how to use those utilities that are used by Debian source packages, please see the hello example package.


C.1.1 dpkg-source - packs and unpacks Debian source packages

This program is frequently used by hand, and is also called from package-independent automated building scripts such as dpkg-buildpackage.

To unpack a package it is typically invoked with

       dpkg-source -x .../path/to/filename.dsc

with the filename.tar.gz and filename.diff.gz (if applicable) in the same directory. It unpacks into package-version, and if applicable package-version.orig, in the current directory.

To create a packed source archive it is typically invoked:

       dpkg-source -b package-version

This will create the .dsc, .tar.gz and .diff.gz (if appropriate) in the current directory. dpkg-source does not clean the source tree first - this must be done separately if it is required.

See also Source packages as archives, Section C.3.


C.1.2 dpkg-buildpackage - overall package-building control script

dpkg-buildpackage is a script which invokes dpkg-source, the debian/rules targets clean, build and binary, dpkg-genchanges and pgp to build a signed source and binary package upload.

It is usually invoked by hand from the top level of the built or unbuilt source directory. It may be invoked with no arguments; useful arguments include:

-uc, -us
Do not PGP-sign the .changes file or the source package .dsc file, respectively.
-ppgp-command
Invoke pgp-command instead of finding pgp on the PATH. pgp-command must behave just like pgp.
-rroot-command
When root privilege is required, invoke the command root-command. root-command should invoke its first argument as a command, from the PATH if necessary, and pass its second and subsequent arguments to the command it calls. If no root-command is supplied then dpkg-buildpackage will take no special action to gain root privilege, so that for most packages it will have to be invoked as root to start with.
-b, -B
Two types of binary-only build and upload - see dpkg-source(1).

C.1.3 dpkg-gencontrol - generates binary package control files

This program is usually called from debian/rules (see The Debianised source tree, Section C.2) in the top level of the source tree.

This is usually done just before the files and directories in the temporary directory tree where the package is being built have their permissions and ownerships set and the package is constructed using dpkg-deb/ [65].

dpkg-gencontrol must be called after all the files which are to go into the package have been placed in the temporary build directory, so that its calculation of the installed size of a package is correct.

It is also necessary for dpkg-gencontrol to be run after dpkg-shlibdeps so that the variable substitutions created by dpkg-shlibdeps in debian/substvars are available.

For a package which generates only one binary package, and which builds it in debian/tmp relative to the top of the source package, it is usually sufficient to call dpkg-gencontrol.

Sources which build several binaries will typically need something like:

       dpkg-gencontrol -Pdebian/tmp-pkg -ppackage

The -P tells dpkg-gencontrol that the package is being built in a non-default directory, and the -p tells it which package's control file should be generated.

dpkg-gencontrol also adds information to the list of files in debian/files, for the benefit of (for example) a future invocation of dpkg-genchanges.


C.1.4 dpkg-shlibdeps - calculates shared library dependencies

This program is usually called from debian/rules just before dpkg-gencontrol (see The Debianised source tree, Section C.2), in the top level of the source tree.

Its arguments are executables. [66] for which shared library dependencies should be included in the binary package's control file.

If some of the found shared libraries should only warrant a Recommends or Suggests, or if some warrant a Pre-Depends, this can be achieved by using the -ddependency-field option before those executable(s). (Each -d option takes effect until the next -d.)

dpkg-shlibdeps does not directly cause the output control file to be modified. Instead by default it adds to the debian/substvars file variable settings like shlibs:Depends. These variable settings must be referenced in dependency fields in the appropriate per-binary-package sections of the source control file.

For example, the procps package generates two kinds of binaries, simple C binaries like ps which require a predependency and full-screen ncurses binaries like top which require only a recommendation. It can say in its debian/rules:

       dpkg-shlibdeps -dPre-Depends ps -dRecommends top

and then in its main control file debian/control:

       ...
       Package: procps
       Pre-Depends: ${shlibs:Pre-Depends}
       Recommends: ${shlibs:Recommends}
       ...

Sources which produce several binary packages with different shared library dependency requirements can use the -pvarnameprefix option to override the default shlib: prefix (one invocation of dpkg-shlibdeps per setting of this option). They can thus produce several sets of dependency variables, each of the form varnameprefix:dependencyfield, which can be referred to in the appropriate parts of the binary package control files.


C.1.5 dpkg-distaddfile - adds a file to debian/files

Some packages' uploads need to include files other than the source and binary package files.

dpkg-distaddfile adds a file to the debian/files file so that it will be included in the .changes file when dpkg-genchanges is run.

It is usually invoked from the binary target of debian/rules:

       dpkg-distaddfile filename section priority

The filename is relative to the directory where dpkg-genchanges will expect to find it - this is usually the directory above the top level of the source tree. The debian/rules target should put the file there just before or just after calling dpkg-distaddfile.

The section and priority are passed unchanged into the resulting .changes file. See Section and Priority, Section D.2.9.


C.1.6 dpkg-genchanges - generates a .changes upload control file

This program is usually called by package-independent automatic building scripts such as dpkg-buildpackage, but it may also be called by hand.

It is usually called in the top level of a built source tree, and when invoked with no arguments will print out a straightforward .changes file based on the information in the source package's changelog and control file and the binary and source packages which should have been built.


C.1.7 dpkg-parsechangelog - produces parsed representation of a changelog

This program is used internally by dpkg-source et al. It may also occasionally be useful in debian/rules and elsewhere. It parses a changelog, debian/changelog by default, and prints a control-file format representation of the information in it to standard output.


C.1.8 dpkg-architecture - information about the build and host system

This program can be used manually, but is also invoked by dpkg-buildpackage or debian/rules to set to set environment or make variables which specify the build and host architecture for the package building process.


C.2 The Debianised source tree

The source archive scheme described later is intended to allow a Debianised source tree with some associated control information to be reproduced and transported easily. The Debianised source tree is a version of the original program with certain files added for the benefit of the Debianisation process, and with any other changes required made to the rest of the source code and installation scripts.

The extra files created for Debian are in the subdirectory debian of the top level of the Debianised source tree. They are described below.


C.2.1 debian/rules - the main building script

This file is an executable makefile, and contains the package-specific recipies for compiling the package and building binary package(s) out of the source.

It must start with the line #!/usr/bin/make -f, so that it can be invoked by saying its name rather than invoking make explicitly.

Since an interactive debian/rules script makes it impossible to autocompile that package and also makes it hard for other people to reproduce the same binary package, all required targets have to be non-interactive. At a minimul, required targets are the ones called by dpkg-buildpackage, namely, clean, binary, binary-arch, and build. It also follows that any target that these targets depend on must also be non-interactive.

The targets which are required to be present are:

build
This should perform all non-interactive configuration and compilation of the package. If a package has an interactive pre-build configuration routine, the Debianised source package should be built after this has taken place, so that it can be built without rerunning the configuration.

A package may also provide both of the targets build-arch and build-indep. The build-arch target, if provided, should perform all non-interactive configuration and compilation required for producing all architecture-dependant binary packages (those packages for which the body of the Architecture field in debian/control is not all). Similarly, the build-indep target, if provided, should perform all non-interactive configuration and compilation required for producing all architecture-independent binary packages (those packages for which the body of the Architecture field in debian/control is all). The build target should depend on those of the targets build-arch and build-indep that are provided in the rules file.

If one or both of the targets build-arch and build-indep are not provided, then invoking debian/rules with one of the not-provided targets as arguments should produce a exit status code of 2. Usually this is provided automatically by make if the target is missing.

For some packages, notably ones where the same source tree is compiled in different ways to produce two binary packages, the build target does not make much sense. For these packages it is good enough to provide two (or more) targets (build-a and build-b or whatever) for each of the ways of building the package, and a build target that does nothing. The binary target will have to build the package in each of the possible ways and make the binary package out of each.

The targets build, build-arch and build-indep target must not do anything that might require root privilege.

The build target may need to run clean first - see below.

When a package has a configuration routine that takes a long time, or when the makefiles are poorly designed, or when build needs to run clean first, it is a good idea to touch build when the build process is complete. This will ensure that if debian/rules build is run again it will not rebuild the whole program.

binary, binary-arch, binary-indep
The binary target should be all that is necessary for the user to build the binary package. All these targets are required to be non-interactive. It is split into two parts: binary-arch builds the packages' output files which are specific to a particular architecture, and binary-indep builds those which are not.

binary should usually be a target with no commands which simply depends on binary-arch and binary-indep.

Both binary-* targets should depend on the build target, above, so that the package is built if it has not been already. It should then create the relevant binary package(s), using dpkg-gencontrol to make their control files and dpkg-deb to build them and place them in the parent of the top level directory.

If one of the binary-* targets has nothing to do (this will be always be the case if the source generates only a single binary package, whether architecture-dependent or not) it must still exist, but should always succeed.

Binary packages (from old Packaging Manual), Appendix B describes how to construct binary packages.

The binary targets must be invoked as root.

clean
This should undo any effects that the build and binary targets may have had, except that it should leave alone any output files created in the parent directory by a run of binary. This target is required to be non-interactive.

If a build file is touched at the end of the build target, as suggested above, it must be removed as the first thing that clean does, so that running build again after an interrupted clean doesn't think that everything is already done.

The clean target must be invoked as root if binary has been invoked since the last clean, or if build has been invoked as root (since build may create directories, for example).

get-orig-source (optional)
This target fetches the most recent version of the original source package from a canonical archive site (via FTP or WWW, for example), does any necessary rearrangement to turn it into the original source tarfile format described below, and leaves it in the current directory.

This target may be invoked in any directory, and should take care to clean up any temporary files it may have left.

This target is optional, but providing it if possible is a good idea.

The build, binary and clean targets must be invoked with a current directory of the package's top-level directory.

Additional targets may exist in debian/rules, either as published or undocumented interfaces or for the package's internal use.

The architecture we build on and build for is determined by make variables via dpkg-architecture (see dpkg-architecture - information about the build and host system, Section C.1.8). You can get the Debian architecture and the GNU style architecture specification string for the build machine as well as the host machine. Here is a list of supported make variables:

where * is either BUILD for specification of the build machine or HOST for specification of the machine we build for.

Backward compatibility can be provided in the rules file by setting the needed variables to suitable default values, please refer to the documentation of dpkg-architecture for details.

It is important to understand that the DEB_*_ARCH string does only determine which Debian architecture we build on resp. for. It should not be used to get the CPU or System information, the GNU style variables should be used for that.


C.2.2 debian/control

This file contains version-independent details about the source package and about the binary packages it creates.

It is a series of sets of control fields, each syntactically similar to a binary package control file. The sets are separated by one or more blank lines. The first set is information about the source package in general; each subsequent set describes one binary package that the source tree builds.

The syntax and semantics of the fields are described below in Control files and their fields (from old Packaging Manual), Appendix D.

The general (binary-package-independent) fields are:

The per-binary-package fields are:

These fields are used by dpkg-gencontrol to generate control files for binary packages (see below), by dpkg-genchanges to generate the .changes file to accompany the upload, and by dpkg-source when it creates the .dsc source control file as part of a source archive.

The fields here may contain variable references - their values will be substituted by dpkg-gencontrol, dpkg-genchanges or dpkg-source when they generate output control files. See debian/substvars and variable substitutions, Section C.2.4 for details.


C.2.2.1 User-defined fields

Additional user-defined fields may be added to the source package control file. Such fields will be ignored, and not copied to (for example) binary or source package control files or upload control files.

If you wish to add additional unsupported fields to these output files you should use the mechanism described here.

Fields in the main source control information file with names starting X, followed by one or more of the letters BCS and a hyphen -, will be copied to the output files. Only the part of the field name after the hyphen will be used in the output file. Where the letter B is used the field will appear in binary package control files, where the letter S is used in source package control files and where C is used in upload control (.changes) files.

For example, if the main source information control file contains the field

       XBS-Comment: I stand between the candle and the star.

then the binary and source package control files will contain the field

       Comment: I stand between the candle and the star.

C.2.3 debian/changelog

This file records the changes to the Debian-specific parts of the package [67].

It has a special format which allows the package building tools to discover which version of the package is being built and find out other release-specific information.

That format is a series of entries like this:

       package (version) distribution(s); urgency=urgency
     
        * change details
        more change details
        * even more change details
     	      
       -- maintainer name and email address  date

package and version are the source package name and version number.

distribution(s) lists the distributions where this version should be installed when it is uploaded - it is copied to the Distribution field in the .changes file. See Distribution, Section D.2.14.

urgency is the value for the Urgency field in the .changes file for the upload. See Urgency, Section D.2.15. It is not possible to specify an urgency containing commas; commas are used to separate keyword=value settings in the dpkg changelog format (though there is currently only one useful keyword, urgency).

The change details may in fact be any series of lines starting with at least two spaces, but conventionally each change starts with an asterisk and a separating space and continuation lines are indented so as to bring them in line with the start of the text above. Blank lines may be used here to separate groups of changes, if desired.

The maintainer name and email address should not necessarily be those of the usual package maintainer. They should be the details of the person doing this version. The information here will be copied to the .changes file, and then later used to send an acknowledgement when the upload has been installed.

The date should be in RFC822 format [68]; it should include the timezone specified numerically, with the timezone name or abbreviation optionally present as a comment.

The first `title' line with the package name should start at the left hand margin; the `trailer' line with the maintainer and date details should be preceded by exactly one space. The maintainer details and the date must be separated by exactly two spaces.

An Emacs mode for editing this format is available: it is called debian-changelog-mode. You can have this mode selected automatically when you edit a Debian changelog by adding a local variables clause to the end of the changelog.


C.2.3.1 Defining alternative changelog formats

It is possible to use a different format to the standard one, by providing a parser for the format you wish to use.

In order to have dpkg-parsechangelog run your parser, you must include a line within the last 40 lines of your file matching the Perl regular expression: \schangelog-format:\s+([0-9a-z]+)\W The part in parentheses should be the name of the format. For example, you might say:

       @@@ changelog-format: joebloggs @@@

Changelog format names are non-empty strings of alphanumerics.

If such a line exists then dpkg-parsechangelog will look for the parser as /usr/lib/dpkg/parsechangelog/format-name or /usr/local/lib/dpkg/parsechangelog/format-name; it is an error for it not to find it, or for it not to be an executable program. The default changelog format is dpkg, and a parser for it is provided with the dpkg package.

The parser will be invoked with the changelog open on standard input at the start of the file. It should read the file (it may seek if it wishes) to determine the information required and return the parsed information to standard output in the form of a series of control fields in the standard format. By default it should return information about only the most recent version in the changelog; it should accept a -vversion option to return changes information from all versions present strictly after version, and it should then be an error for version not to be present in the changelog.

The fields are:

If several versions are being returned (due to the use of -v), the urgency value should be of the highest urgency code listed at the start of any of the versions requested followed by the concatenated (space-separated) comments from all the versions requested; the maintainer, version, distribution and date should always be from the most recent version.

For the format of the Changes field see Changes, Section D.2.18.

If the changelog format which is being parsed always or almost always leaves a blank line between individual change notes these blank lines should be stripped out, so as to make the resulting output compact.

If the changelog format does not contain date or package name information this information should be omitted from the output. The parser should not attempt to synthesise it or find it from other sources.

If the changelog does not have the expected format the parser should exit with a nonzero exit status, rather than trying to muddle through and possibly generating incorrect output.

A changelog parser may not interact with the user at all.


C.2.4 debian/substvars and variable substitutions

When dpkg-gencontrol, dpkg-genchanges and dpkg-source generate control files they do variable substitutions on their output just before writing it. Variable substitutions have the form ${variable-name}. The optional file debian/substvars contains variable substitutions to be used; variables can also be set directly from debian/rules using the -V option to the source packaging commands, and certain predefined variables are available.

The is usually generated and modified dynamically by debian/rules targets; in this case it must be removed by the clean target.

See dpkg-source(1) for full details about source variable substitutions, including the format of debian/substvars.


C.2.5 debian/files

This file is not a permanent part of the source tree; it is used while building packages to record which files are being generated. dpkg-genchanges uses it when it generates a .changes file.

It should not exist in a shipped source package, and so it (and any backup files or temporary files such as files.new [69]) should be removed by the clean target. It may also be wise to ensure a fresh start by emptying or removing it at the start of the binary target.

dpkg-gencontrol adds an entry to this file for the .deb file that will be created by dpkg-deb from the control file that it generates, so for most packages all that needs to be done with this file is to delete it in clean.

If a package upload includes files besides the source package and any binary packages whose control files were made with dpkg-gencontrol then they should be placed in the parent of the package's top-level directory and dpkg-distaddfile should be called to add the file to the list in debian/files.


C.2.6 debian/tmp

This is the canonical temporary location for the construction of binary packages by the binary target. The directory tmp serves as the root of the filesystem tree as it is being constructed (for example, by using the package's upstream makefiles install targets and redirecting the output there), and it also contains the DEBIAN subdirectory. See Creating package files - dpkg-deb, Section B.1.

If several binary packages are generated from the same source tree it is usual to use several debian/tmpsomething directories, for example tmp-a or tmp-doc.

Whatever tmp directories are created and used by binary must of course be removed by the clean target.


C.3 Source packages as archives

As it exists on the FTP site, a Debian source package consists of three related files. You must have the right versions of all three to be able to use them.

Debian source control file - .dsc
This file contains a series of fields, identified and separated just like the fields in the control file of a binary package. The fields are listed below; their syntax is described above, in Control files and their fields (from old Packaging Manual), Appendix D.

The source package control file is generated by dpkg-source when it builds the source archive, from other files in the source package, described above. When unpacking it is checked against the files and directories in the other parts of the source package, as described below.

Original source archive - package_upstream-version.orig.tar.gz
This is a compressed (with gzip -9) tar file containing the source code from the upstream authors of the program. The tarfile unpacks into a directory package-upstream-version.orig, and does not contain files anywhere other than in there or in its subdirectories.
Debianisation diff - package_upstream_version-revision.diff.gz
This is a unified context diff (diff -u) giving the changes which are required to turn the original source into the Debian source. These changes may only include editing and creating plain files. The permissions of files, the targets of symbolic links and the characteristics of special files or pipes may not be changed and no files may be removed or renamed.

All the directories in the diff must exist, except the debian subdirectory of the top of the source tree, which will be created by dpkg-source if necessary when unpacking.

The dpkg-source program will automatically make the debian/rules file executable (see below).

If there is no original source code - for example, if the package is specially prepared for Debian or the Debian maintainer is the same as the upstream maintainer - the format is slightly different: then there is no diff, and the tarfile is named package_version.tar.gz and contains a directory package-version.


C.4 Unpacking a Debian source package without dpkg-source

dpkg-source -x is the recommended way to unpack a Debian source package. However, if it is not available it is possible to unpack a Debian source archive as follows:

  1. Untar the tarfile, which will create a .orig directory.
  2. Rename the .orig directory to package-version.
  3. Create the subdirectory debian at the top of the source tree.
  4. Apply the diff using patch -p0.
  5. Untar the tarfile again if you want a copy of the original source code alongside the Debianised version.

It is not possible to generate a valid Debian source archive without using dpkg-source. In particular, attempting to use diff directly to generate the .diff.gz file will not work.


C.4.1 Restrictions on objects in source packages

The source package may not contain any hard links [70] [71], device special files, sockets or setuid or setgid files. [72]

The source packaging tools manage the changes between the original and Debianised source using diff and patch. Turning the original source tree as included in the .orig.tar.gz into the debianised source must not involve any changes which cannot be handled by these tools. Problematic changes which cause dpkg-source to halt with an error when building the source package are:

Changes which cause dpkg-source to print a warning but continue anyway are:

Changes which are not represented, but which are not detected by dpkg-source, are:

The debian directory and debian/rules are handled specially by dpkg-source - before applying the changes it will create the debian directory, and afterwards it will make debian/rules world-exectuable.


[ previous ] [ Contents ] [ 1 ] [ 2 ] [ 3 ] [ 4 ] [ 5 ] [ 6 ] [ 7 ] [ 8 ] [ 9 ] [ 10 ] [ 11 ] [ 12 ] [ 13 ] [ A ] [ B ] [ C ] [ D ] [ E ] [ F ] [ G ] [ next ]

Debian Policy Manual

version 3.5.6.1, 2002-03-14
Ian Jackson ijackson@gnu.ai.mit.edu
Christian Schwarz schwarz@debian.org
revised: David A. Morris bweaver@debian.org
The Debian Policy mailing List debian-policy@lists.debian.org